A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

WA govt shark policy 'based on Jaws'

An academic who's doing a thesis on the politics of shark attacks has compared Western Australia's policy to the Hollywood blockbuster Jaws.

The University of Sydney's Christopher Neff says WA's "imminent threat" policy is based on the Steven Spielberg movie about a rogue man-eating shark, which was adapted from the 1974 novel by Peter Benchley.

He says it reflects three themes from the film: that sharks mean to kill, all encounters between humans and sharks are fatal, and the only solution is to kill the sharks.

"This fiction serves an important political purpose because films allow politicians to rely on familiar narratives following shark bites to blame individual sharks in order to make the events governable and to trump evidence-based science," he said.

The WA government recently withdrew an application to the federal government to extend its controversial drumline program, which uses baited fishhooks, but wants blanket permission to kill sharks when their presence in the water is deemed too risky to humans.

A spokeswoman for federal Environment Minister Greg Hunt says the Commonwealth is yet to receive the proposal.

She rejected a claim by activist group Sea Shepherd that the WA government deployed drumlines off Esperance about 90 minutes before receiving written permission to kill two white sharks following an attack on surfer Sean Pollard on October 2.